Electrical batteries or power storage devices have to be recharged at regular intervals. In this case, the term “electric vehicle” should be understood to mean both electric cars and also electric scooters or electric bicycles etc. In respect of electric cars, the term “electric vehicle” covers both purely electrically operated vehicles and also so-called hybrid vehicles which have an additional drive, for example an internal combustion engine, in addition to an electric drive.
On account of the increasing popularity of electric vehicles, new requirements are being placed on the charging infrastructure, which is also called Electric Vehicle Supply Equipment, for short: EVSE, in respect of the charging process of an electric vehicle, in particular an electric car. The term EVSE should be understood to mean—in accordance with IEC Standard 61851 (DIN EN 61851)—a power supply device for charging electric road vehicles, including plug-in hybrid electric vehicles.
These power supply devices include, for example, charging stations, so-called wall boxes (for mounting in garages for example) or else the charging cable for connection to the electric vehicle. This charging infrastructure or EVSE therefore forms the interface between the load, electric vehicle, and the familiar electrical installation. A key requirement for the manner of operation of the charging infrastructure concerns, for example, a charging time for the electric vehicle which is as short as possible. This necessarily leads to a relatively high charging current which has to be made available over a relatively long charging time. Charging stations which are designed for charging electric vehicles in particular are designed for high charging currents of this kind.
When charging electric vehicles via a conventional domestic electrical installation, for example via so-called Schuko plug sockets which are very common in Germany, a permanently high charging current constitutes extreme loading since the conventional domestic electrical installation is not developed and designed for loads of this kind, that is to say for charging currents of such a level which flow over such a long charging time. This also applies, in particular, when using a so-called “inline module” which is carried along by the majority of electric vehicles as an “emergency charging unit”. The electric vehicle can be connected to a conventional domestic connection plug socket with the aid of this “inline module” and can be charged by way of it. On account of the associated high long-term loading on the electrical installation—in particular on a 230 V domestic installation—the automobile industry requires temperature monitoring in so-called domestic connection plugs of the charging cable which is provided for contact to be made with the domestic installation at the supply system end, in order to ensure a safe charging process and to protect the plug socket against overheating and possibly against catching fire.
Currently available charging cables for charging the electric vehicle via a domestic plug socket therefore have a temperature sensor on the domestic connection plug, the temperature sensor registering a temperature increase in the region of the plug or the plug socket and sending a corresponding signal to a control device of the charging cable or of the electric vehicle. For this reason, the connection of an extension cable or a plug socket adapter on the domestic connection plug is not permissible either since it is not possible to ensure temperature monitoring of the domestic connection plug socket in this case.
Therefore, the charging cable or the inline module is, however, fixed on a specific domestic connection plug and therefore not suitable for any design of a domestic connection plug socket. This is problematical in as much as there are a large number of plug/plug socket variants which differ from country to country in Europe—but also worldwide. For example, “type F plugs” (so-called Schuko plugs, also called CEE 7/4 plugs), “type C plugs” (so-called Euro plugs, also called CEE 7/16 plugs) or CEE plugs (in accordance with DIN/EN/IEC 60309) can be used in Germany. In this case, the term “Schuko” commonly used in Germany is an acronym for the German term “Schutzkontakt”, “protective contact” in English, and describes a system of plugs and plug sockets which is very common in Europe. However, in France “type E plugs” (CEE 7/5 plugs) and in Great Britain and the Commonwealth “type G plugs” (so-called Commonwealth plugs) are predominantly used as standardized electrical infrastructure plugs for domestic applications. This makes it considerably more difficult to use a specific inline module for cross-border journeys.